Okay, let's tackle this math problem. We're starting with 274740 and subtracting 42029.

Step 1: We'll start by subtracting the digit 9 and the borrow 0 from 0 in column 1 and get -9.
We add -9 to 10 and get 1 as the first digit of the result.

Step 2: We'll start by subtracting the digit 2 and the borrow 1 from 4 in column 2 and get 1.
1 is the next digit of our result.

Step 3: We'll start by subtracting the digit 0 and the borrow 0 from 7 in column 3 and get 7.
7 is the next digit of our result.

Step 4: We'll start by subtracting the digit 2 and the borrow 0 from 4 in column 4 and get 2.
2 is the next digit of our result.

Step 5: We'll start by subtracting the digit 4 and the borrow 0 from 7 in column 5 and get 3.
3 is the next digit of our result.

Step 6: We'll start by subtracting the digit 0 and the borrow 0 from 2 in column 6 and get 2.
2 is the next digit of our result.

So, 274740 - 42029 = 232711.